Time allowed: 3 hours · Maximum marks: 80 · AW-10M-BP-70027
Mathematics (Standard): Board Exam Practice Paper · AW-10M-BP-70027 · For the parent or teacher: award the marks shown for each step, even when the final answer is wrong.
| Q | Answer and marks for each step | Marks |
|---|---|---|
| Section A: 20 questions of 1 mark each | ||
| 1 | (d) 108 LCM = 18 × 2 × 3 = 108 | 1 |
| 2 | (a) 10 (−7)2 + k × (−7) + 21 = 0, so k = 10 | 1 |
| 3 | (c) k = 24 the second equation must be 3 times the first | 1 |
| 4 | (b) real and distinct b2 − 4ac = 49 > 0 | 1 |
| 5 | (d) −520 26/2 × (2 × 5 + 25 × (−2)) = −520 | 1 |
| 6 | (d) AA | 1 |
| 7 | (b) 17 units √(225 + 64) = 17 | 1 |
| 8 | (b) 5 √(9 + 16) = 5 | 1 |
| 9 | (c) 3/4 + √3/3 1/√3 + 3/4 | 1 |
| 10 | (a) between 0 and 1 the opposite side is shorter than the hypotenuse | 1 |
| 11 | (b) 30° tan θ = 21 ÷ 21√3, so θ = 30° | 1 |
| 12 | (b) 130° ∠OAP = ∠OBP = 90°, so ∠AOB = 360° − 180° − 50° = 130° | 1 |
| 13 | (d) 2πr its circumference | 1 |
| 14 | (d) 35–40 the highest frequency is 20 | 1 |
| 15 | (c) 57.71 404 ÷ 7 = 57.71 | 1 |
| 16 | (c) 40–50 n = 64, n/2 = 32; cumulative frequencies 6, 10, 29, 39, 52, 64 | 1 |
| 17 | (a) 3/13 12 such cards out of 52 | 1 |
| 18 | (c) 1/2 3 favourable outcomes out of 6 | 1 |
| 19 | (c) A is true, but R is false. A is true: LCM = 14 × 22 ÷ 2 = 154. R is false. | 1 |
| 20 | (d) A is false, but R is true. A is false: (216 − 9) ÷ 6 = 69/2, which is not a whole number. R is true. | 1 |
| Section B: 5 questions of 2 marks each | ||
| 21 | 32 × 113
| 2 |
| 22 | x = 6, y = 8
| 2 |
| 23 | x = 8
| 2 |
| 23 OR | DA = 20 cm; perimeter 80 cm
| 2 |
| 24 | 52 4/9 cm
| 2 |
| 24 OR | 866 1/4 cm2
| 2 |
| 25 | 20 red marbles
| 2 |
| Section C: 6 questions of 3 marks each | ||
| 26 | Side of the largest tile = HCF(105, 90) = 15 cm; number of tiles = (105 ÷ 15) × (90 ÷ 15) = 7 × 6 = 42.
| 3 |
| 27 | α + β = 1/2 and αβ = −4. (α − β)2 = (α + β)2 − 4αβ = 65/4.
| 3 |
| 28 | QR = 5 cm
| 3 |
| 29 | OP = 82 cm; perimeter of OAPB = 196 cm
| 3 |
| 29 OR | AF = 10 cm, BD = 9 cm, CE = 7 cm
| 3 |
| 30 | Minor segment = 114 cm2; major segment = 1,142 cm2
| 3 |
| 31 | Mode = 32.5
| 3 |
| 31 OR | Mean = 26.25
| 3 |
| Section D: 4 questions of 5 marks each | ||
| 32 | Let the integers be x and x + 2: x2 + (x + 2)2 = 2452, that is, 2x2 + 4x − 2448 = 0, so x2 + 2x − 1224 = 0, so (x − 34)(x + 36) = 0, giving x = 34 or x = −36. The integers are positive, so x = −36 is rejected. The integers are 34 and 36.
| 5 |
| 32 OR | Fixed charge = Rs 40; charge per kilometre = Rs 17. For 18 km: Rs 40 + 18 × Rs 17 = Rs 346.
| 5 |
| 33 | Sn = n/2 [2a + (n − 1)d] with a = 220, d = 45: n/2 [440 + (n − 1) × 45] = 7175, that is, 9n2 + 79n − 2870 = 0, so n = 14 or n = −205/9. The number of months must be a natural number, so n = −205/9 is rejected; n = 14 months. The 14th term is 220 + 13 × 45 = 805, so Rs 805 for the last month.
| 5 |
| 34 | Join ZW, meeting LG at B. In △ZDW, LB ∥ DW, so ZL/LD = ZB/BW (BPT). In △WZT, BG ∥ ZT, so WB/BZ = WG/GT, that is ZB/BW = TG/GW. Hence ZL/LD = TG/GW. TG = 9 cm and GW = 15 cm.
| 5 |
| 35 | Distance travelled = 66(√3 − 1) m ≈ 48.2 m; distance at the second observation = 66 m
| 5 |
| 35 OR | Height of the chimney = 24(√3 + 1) m ≈ 65.5 m; distance = 24√3 m ≈ 41.5 m
| 5 |
| Section E: 3 case-based questions of 4 marks each | ||
| 36 (i) | 13 km
| 1 |
| 36 (ii) | (−12.5, −4)
| 1 |
| 36 (iii) | HS + SM = 2√5 + 3√5 = 5√5 = HM, so H, S and M are collinear
| 2 |
| 36 (iii) OR | Ratio 9 : 1; point (−14.5, 0)
| 2 |
| 37 (i) |
| 1 |
| 37 (ii) |
| 1 |
| 37 (iii) | 40 m
| 2 |
| 37 (iii) OR | 20√3 m ≈ 34.6 m
| 2 |
| 38 (i) | 50 cm
| 1 |
| 38 (ii) | 6,600 cm2
| 1 |
| 38 (iii) | 12,144 cm2
| 2 |
| 38 (iii) OR | 108,108 cm3
| 2 |